With or without Predator

Not gonna make a review on the entire Alien saga...I have a life...sometimes. But I just need to vent the following: 

WHY in the hell did they made impossible for the fans to connect the crossovers to the main story. The "Ripley" movies are compatible with the Prometheus one's and I love both those sections much more then I enjoy the Predators trilogy. Nonetheless my little geek is screaming cuz if [spoiler] David created the xenomorph around 2100 how in hell can the predators have that frozen freek in the basement of that pyramid. They are reducing 3 movies to a fever dream. Sad, just sad.

I do prefer the hole creation of the creation of the creation ark but the predator's movies had already established that humans were "made". Was it that big of a stretch?

Anyway I might return to the topic cuz there's so much I wanna say about this saga. And I still need to see Romulus.

Bye